Before I go ahead and construct version 3 of the amp, I need to make a lab power supply with variable plus and minus voltage outputs and ammeters for measuring the current drawn.
I’ll be using the case from an Apple G5 computer that is now defunct. The parts will mostly come from an amp I made three decades ago using ILP MOSFET (MOS 248) PA blocks. The transformers are rated at 7A per channel continuous (so no problems with the power ratings) and there are eight 22,000µF electrolytic capacitors per channel.
The transformer outputs of plus and minus 42V will be available but these will also feed, via switches, LM317 and LM337 variable voltage regulators. I may also provide some form of current limiting.
This shouldn’t take too long, the most time consuming part is documenting it all and ordering parts I do not have. Once finished I will publish the circuit diagram for others to use freely (not that this information isn’t out there anyway).
In the meantime here is the (side) panel layout that I’m working on right now. Photographs will come later.